Hi there!

I´m trying to design a setup that will run on solar power, so I can get data to my remote cabin. There is a weak 4G and 5G signal on an island 500 meters from my cabin. No power anywhere, just solar.
I want to set up a cellular antenna like the ATL 5G R16, and a wifi long range antenna.
Please have a look at the image and let me know if there are any holes in my thinking, or other ways of doing things!

Instead of NetMetal, get another device with a built-in antenna

The ATL 5G R16 has seemingly only one port, so your topology with two connections to it cannot be done.

The Netmetal Ax has also only one port, so you will need to connect both devices to the "solar switch".

BTW that Ubiquity thingy has 10/100 Mb ports, whilst both the ATL and Netmetal have 1 Gb ones, though very likely the 4G/5G bandwidth won't be very fast you are introducing a physical/hardware bottle-neck.

No idea if suitable "solar" Gb switches similar to the Ubiquity one exist, I believe that if they have Gb port, they also have 802.3af/at PoE (that would be good for the ATL but not for the Netmetal).

Maybe it would be worth exploring the use of a "normal" solar/battery controller and a "normal" (PoE) switch like the RB260GSP.

About Netmetal Ax antenna(s) considerations, look at this recent thread (only seemingly unrelated):
viewtopic.php?t=217155

Use victron energy mppt solar controller and lifepo4 batteries.

Thanks everyone for the info. Much appreciated! I love the form factor of the Ubuquiti, since the install needs to super stealth and I also like the remote admin tools.

Speed is not a big issue, I mostly need connection for messaging and ip calls, plus downloading a PDF manual or asking dumb questions on forums sometimes

Would there be a different antenna that’d be better suited?
Around 500m distance, on approx same elevation.

Around 500m distance, on approx same elevation.

Well, you would need a directional antenna (actually two of them if using the netmetal) to get the signal at 500 m, point is that directional antennas are directional (i.e. you will cover an area the size of a coin or of a dish.

If I get right now your situation, you need a PtP connection between that remote LTE device and a second (solar) install at your cabin.

Loosely something *like* the so called wireless wire:
https://mikrotik.com/product/wireless_wire_cube_pro

See also:
https://cdn.mikrotik.com/web-assets/pro ... 250333.pdf

Since you don't need (and won't have as it comes from LTE) much speed in the conneciton, and surely you have not much congestion/interference from other devices, you can get away with much cheaper devices, not 60 GHz, but "normal" 2.4 or 5 Ghz devices.

Probably a couple of these sxtsq 5ax would do nicely without spending too much :
https://mikrotik.com/product/sxtsq_5ax

Use victron energy mppt solar controller and lifepo4 batteries.

I like the Victron's too - we have a few setups with their MPPTs and LoRaWAN connection (to remote KNOTs). And, we have a couple setups that use AGM batteries, and they work fine with Victron.

Only downside with victron is you need to get a separate part to get ethernet. In our case, we use LoRaWAN module to the MPPT & have remote KNOTs with stable internet that relay Victron stats to their VRM portal... so sunMAX be a downgrade in my case. But if you don't want out-of-band management of the solar, the sunMAX does seem more plug-and-play.

A couple of points you may not have considered...

1/ You haven't stated if you are on the island that has the 4/5G signal, or that's where the signal is but you are wanting beam it back to the mainland, so to speak.
If you are on the mainland, and the signal needs to cross 500m of water then you probably need to consider how much signal refraction you'll get across the water. If you are receiving on the island as well, it'll would probably help to know a bit more of the topography and whether there is clear line of site between where you'll place the LTE antenna and where you'll be receiving the signal.

2/ If you have poor signal on the best spot on the island, I would consider using the lowest band frequencies coming in from the celltower. Lower frequencies tend to be stronger and more reliable over distance than high frequencies. So, if your provider uses 700 or 800MHz they are likely to be more usable than those 1800MHz and above. This would then limit you to 4G at lower speed, but should be more reliable. Depending on where you are in the world, 5G would probably be a pipe dream with weak incoming signal. Bit of a trade off. If you find you can do -65dB or better using higher frequencies with the ATL, then they might hold. -65dB is the lowest I would go for LTE if I were connecting into a PTP link.

If you find you can do -65dB or better using higher frequencies with the ATL, then they might hold. -65dB is the lowest I would go for LTE if I were connecting into a PTP link.

There are two dignal strength quantities in LTE: RSSI (which includes all the signal in the used frequency channel and is thud useless when assessing signal properties ... sadly it's the quantity some of devices report as signal strength) and RSRP (signal strength of particular 4G cell used for your connection). For a stable LTE link, RSRP higher than around -85dBm is enough ... if MNO doesn't set cell Tx power too high (some do to artificially increase network coverage) in which case uplink will struggle. Then there's secondary quantity: signal quality, most often reported as RSRQ and should ideally be higher than -10dB for decent performance (highest realistic value is around -3dB).
Achievable throughput is limited by SINR, which can't be measured/calculated directly but is loosely correlates with RSRP and RSRQ (for both the higher measured values, the higher SINR and thus higher throughput).

When it comes to ATL: sadly all MT antennas have poor gain in the lower frequency band ... dish antennas (as with ATL) included. So even if antenna gain is specced decently high (16dBi in case of ATL 5G R16), it'll be much worse in lower bands, e.g. 700MHz or 800MHz (which, as @KiwiBloke mentioned, are more likely to offer stable service in remote locations). This might come as a disappointment when comparing measurements to ones taken by typical smart phones so before being sure that ATL (or any other MT antenna) will work it's necessary to verify that by using the intended equipment.

Wow, I´m floored by the amount of knowledge and willingness to share and advice here. What a great forum! Thanks everyone.
I´ve dug up an old-ish MT DISC Lite5 ac point-to-point antenna that I will use for sending IP network via wireless cable.
Then the question of the cell reception. Are there any good antennas for the low range, 700 MHz signal?

I´ve received 4G and 5G on the island, but weak, and alternating. It might be that the signal actually bounces on the water from the cell tower far away.

As for transfer from the LTE reception point (on the island) and to our cabin, the cabin is at an elevation of around 20 meters higher than the island,
and I will murder all trees between the antenna and us.

I´ve dug up an old-ish MT DISC Lite5 ac point-to-point antenna that I will use for sending IP network via wireless cable.

Yep, but you (IMHO) need two such devices, one on the island, the other one at the cabin, for PtP links like these having the same device on both ends (when possible) will eliminate a number of possible issues of incompatibility between devices and the link will be inherently "symmetrical".

Back in time, when I worked as radio engineer for incumbent MNO, we had very good experience when using yagi or log-periodic "beasts" for the "low-band" wireless broadband. Such as Iskra P-40 MIMO (for a multi-band variant, look at their antennas with model name P56 or higher).
There are similar offerings from different vendors. Just be sure that vendor publishes decent antenna gain diagrams (relative to frequency) to be sure that antenna does have decent gain at frequencies you're going to use (single-digit gain figure from specs almost always tells about maximum gain in whole supported frequency range and some antennas are very far from having linear gain over the range). Iskra has them in the catalogue, available for download from their product pages.
And yes, for 4G and beyond you'll want to use a MIMO bundle, consisting of 2 antennas placed at 90° angle (sometimes they come as "MIMO dual-port antenna" in single case).

It seems the ATL isn´t the right choice then? I have a MIMO setup somewhere, I can bring that out. Need to get hold of a signal tester first.

Thanks everybody!